10. For a ray of light to be reflected totally internally, angle of incidence must be critical angle. A. Greater than B. Less than C. Equal to D. None of the above.

it doesn't. it was imagined up in the middle ages.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it